Fox River Grove, IL has a population of 4,822 and is the 6,620th largest city in the United States. The population density is 2,766 per sq mi which is 1144% higher than the Illinois average and 2953% higher than the national average. The median age in Fox River Grove is 35 which is approximately 5% lower than the Illinois average of 37. In Fox River Grove, 57% of the population over 15 years of age are married, 88% speak English and 4% speak Spanish. 72% of Fox River Grove residents were born in Illinois, 19% were born out of state, 1% were born outside of the United States and 8% were foreign born.